We have been busy setting up the mail server on one of our web properties. Instead of paying a 3rd party such as Vertical Response $500+ / month, we decided to purchase a $500 software [Active Campaign] and set it up.
Within the next few days, we will post a complete tutorial, but we noticed one issue that others may face and have sleepless nights over.
It is good practice to have a DKIM signature [It is a digital signature verifying that the email did come from your domain - without it, your delivery rates will drop significantly].
Anyhow, you may want to send an email to sa-test@sendmail.net to verify that your email is working ok. It will reply with error messages if applicable.
If you continue to get an error, scroll down to see the header of the reply message – if it says that the time is in the future, go ahead and install ntp and sync your time…